Piezoelectric material, piezoelectric element, liquid ejecting head, liquid ejecting apparatus, ultrasonic sensor, piezoelectric motor, and power generator

ABSTRACT

A piezoelectric material contains a first component that is a rhombohedral crystal and that is configured to have a complex oxide with a perovskite structure and Curie temperature Tc1, a second component that is a crystal other than a rhombohedral crystal and that is configured to have a complex oxide with a perovskite structure and Curie temperature e Tc2, and a third component that is a rhombohedral crystal and that is configured to have a complex oxide with a perovskite structure and Curie temperature Tc3 different from the first component, and in which Tc2 is higher than Tc1, Tc3 is equal to or higher than Tc2, and a value of (0.1×Tc1+0.9×Tc2) is equal to or lower than 280° C.

BACKGROUND

1. Technical Field

The present invention relates to a piezoelectric material used inpiezoelectric elements, or the like mounted in various devices such asactuators, ultrasonic devices such as ultrasonic oscillators, ultrasonicmotors, pressure sensors, and pyroelectric elements such as IR sensors,a piezoelectric element using the material, a liquid ejecting head, aliquid ejecting apparatus, an ultrasonic sensor, a piezoelectric motor,and a power generator.

2. Related Art

A piezoelectric material, which is used as a piezoelectric layer(piezoelectric ceramics) constituting a piezoelectric element, or thelike mounted in various devices such as actuators, ultrasonic devicessuch as ultrasonic oscillators, ultrasonic motors, pressure sensors, andpyroelectric elements such as IR sensors is required to have aremarkable piezoelectric characteristic, and as a representative examplethereof, lead zirconate titanate (PZT) is exemplified.

However, from an environmental sensitivity point of view, apiezoelectric material whose lead content is suppressed is desired. Assuch a lead-free piezoelectric material, there are a piezoelectricmaterial that includes an alkali metal such as K_(x)Na_((1-x))NbO₃, and(Ba, Na)TiO₃, a piezoelectric material such as BiFeO₃—BaTiO₃, and thelike.

With regard to such a piezoelectric material, it is known that aremarkable piezoelectric characteristic can be obtained by using acomposition near a Morphotropic Phase Boundary (MPB). However, in aphase diagram that employs compositions for the horizontal axis andtemperatures for the vertical axis, the MPB line of PZT is substantiallyparallel to the temperature axis or positioned vertical to thecomposition axis, but an MPB line of a lead-free piezoelectric materialis generally inclined with respect to the temperature axis (for example,refer to FIG. 1 of JP-A-2009-215111, or the like). When the MPB isinclined as described above, even if a composition positioned on the MPBline at a specific temperature, for example, room temperature, accordingto a desired characteristic is selected, it is set away from the MPBline on the composition-temperature state diagram when the environmentaltemperature changes, and thus, there is a problem in that there is atemperature area in which a piezoelectric characteristic, and dielectriccharacteristic of an element deteriorates due to changes inenvironmental temperature, generation of heat during usage, or the like.

Thus, from a desire that the MPB line is erect if possible in the phasediagram described above and a desire that a piezoelectric material has aremarkable piezoelectric characteristic and dielectric characteristic ataround a normal temperature (room temperature) and can be used even at ahigh temperature if possible, a piezoelectric material having Curietemperature (Tc) as high as it can be, which is generally inverselyproportional to the piezoelectric characteristic, has been demanded.

For that reason, technologies for improving temperature dependency bylaminating a plurality of piezoelectric materials having differentcompositions have been proposed (refer to JP-A-2003-277143 andJP-A-2011-181764), but the fact that the plurality of differentpiezoelectric materials should be used is a problem.

As described above, currently, there is no lead-free piezoelectricmaterial compared to PZT, and thus, introduction of a lead-freepiezoelectric material having a remarkable piezoelectric characteristicand dielectric characteristic in a wide use environment temperaturerange and having a high Curie temperature has been greatly desired.

Note that such a problem also arises not only in ink jet-type recordingheads but also in other liquid ejecting heads that discharge dropletsother than ink and also arises even in piezoelectric elements used indevices other than liquid ejecting heads.

SUMMARY

An advantage of some aspects of the invention is to provide apiezoelectric material that reduces the burden on the environment, andhas a remarkable piezoelectric characteristic and dielectriccharacteristic in a wide use environment temperature range and a highCurie temperature, a piezoelectric element using the material, a liquidejecting head, a liquid ejecting apparatus, an ultrasonic sensor, apiezoelectric motor, and a power generator.

According to an aspect of the invention, there is provided apiezoelectric material containing a first component that is arhombohedral crystal and that is configured to have a complex oxide witha perovskite structure and Curie temperature is set to be Tc1, a secondcomponent that is a crystal other than a rhombohedral crystal and thatis configured to have a complex oxide with a perovskite structure andCurie temperature is set to be Tc2, and a third component that is arhombohedral crystal and that is configured to have a complex oxide witha perovskite structure but Curie temperature is set to be Tc3 differentfrom the first component, and in which Tc2 is higher than Tc1, Tc3 isequal to or higher than Tc2, and a value of (0.1×Tc1+0.9×Tc2) is equalto or lower than 280° C.

In this case, since the piezoelectric material does not contain lead, anenvironmental burden can be reduced, and the piezoelectric material thathas a remarkable piezoelectric characteristic and dielectriccharacteristic in a wide use environment temperature range and a highCurie temperature is produced.

It is preferable that a composition of the piezoelectric material isnear an MPB line in a phase diagram that employs a ratio of the secondcomponent to the sum of the first component, the second component andthe third component (the second component/(the first component+thesecond component+the third component)) for the horizontal axis, andtemperature for the vertical axis, and Curie temperature Tc4 of thecomposition is equal to or higher than 280° C. In this case, byselecting each component, the piezoelectric material that has aremarkable piezoelectric characteristic and dielectric characteristic ina use environment temperature range and has a high Curie temperature canbe realized, in a wide composition range.

In addition, it is preferable that the molar ratio of (the firstcomponent+the third component) to (the first component+the secondcomponent+the third component) be 0.1 to 0.9. By thusly selecting eachcomponent, the piezoelectric material that has a remarkablepiezoelectric characteristic and dielectric characteristic in a wide useenvironment temperature range and has a high Curie temperature can berealized, in a wide composition range.

In addition, it is preferable that the molar ratio of the thirdcomponent to (the first component+the third component) be 0.05 to 0.49.Accordingly, by thusly selecting each component, the piezoelectricmaterial that has a remarkable piezoelectric characteristic anddielectric characteristic in a wide use environment temperature rangeand has a high Curie temperature can be realized in a wide compositionrange.

In addition, it is preferable that the first component be Ba(XTi)O₃(wherein X is at least one kind selected from Zr, Sn, and Hf), thesecond component be (K, Na)NbO₃ to which at least one kind of Sr and Tiis added, and the third component be Bi(Fe, Mn)O₃. In this case, thepiezoelectric material that has a remarkable piezoelectriccharacteristic and dielectric characteristic in a wide use environmenttemperature range and has a high Curie temperature can be realized morereliably.

In addition, it is preferable that the first component be Ba(Zr, Ti)O₃,the second component be (K, Na)Nb O₃ to which at least one kind of Srand Ti is added, and the third component be Bi(Fe, Mn)O₃. In this case,the piezoelectric material that has a remarkable piezoelectriccharacteristic and dielectric characteristic in a wide use environmenttemperature range and has a high Curie temperature can be realized morereliably.

In addition, it is preferable that the first component be Ba(Sn, Ti)O₃,the second component be (K, Na)NbO₃ to which at least one kind of Li,Sb, and Ta is added, and the third component be Bi(Fe, Mn)O₃. In thiscase, the piezoelectric material that has a remarkable piezoelectriccharacteristic and dielectric characteristic in a wide use environmenttemperature range and has a high Curie temperature can be realized morereliably.

In addition, it is preferable that the first component be Ba(Hf, Ti)O₃,the second component be (K, Na)NbO₃ to which at least one kind of Li, Sband Ta is added, and the third component be Bi(Fe, Mn)O₃. In this case,the piezoelectric material that has a remarkable piezoelectriccharacteristic and dielectric characteristic in a wide use environmenttemperature range and has a high Curie temperature can be realized morereliably.

According to another aspect of the invention, there is provided apiezoelectric element that includes a piezoelectric layer configured tohave the piezoelectric material according to the above-described aspectand an electrode provided on the piezoelectric layer.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the piezoelectric element thatcan maintain excellent characteristics in a wide use environmenttemperature range can be realized.

In addition, according to still another aspect of the invention, thereis provided a liquid ejecting head that includes a pressure generatingchamber that communicates with a nozzle opening and a piezoelectricelement that has a piezoelectric layer and an electrode provided on thepiezoelectric layer, and the piezoelectric layer is formed of thepiezoelectric material according to the above-described aspect.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the liquid ejecting head thatincludes a piezoelectric element that can maintain excellentcharacteristics in a wide use environment temperature range can berealized.

In addition, according to still another aspect of the invention, thereis provided a liquid ejecting apparatus that includes the liquidejecting head according to the above-described aspect.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the liquid ejecting apparatusequipped with a liquid ejecting head that includes a piezoelectricelement that can maintain excellent characteristics in a wide useenvironment temperature range can be realized.

In addition, according to still another aspect of the invention, thereis provided an ultrasonic sensor that includes a vibrating unit thattransmits a displacement to the outside which is caused due to drivingof the piezoelectric element according to the above-described aspect anda matching layer that transmits a generated pressure wave to theoutside.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the ultrasonic sensor equippedwith a piezoelectric element that can maintain excellent characteristicsin a wide use environment temperature range can be realized.

In addition, according to still another aspect of the invention, thereis provided a piezoelectric motor that includes at least a vibrator inwhich the piezoelectric element according to the above-described aspectis arranged, and a moving body contacting the vibrator.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the piezoelectric motorequipped with a piezoelectric element that can maintain excellentcharacteristics in a wide use environment temperature range can berealized.

In addition, according to still another aspect of the invention, thereis provided a power generator that includes an electrode for taking outa charge generated by the piezoelectric element according to theabove-described aspect from the electrode.

In this case, since the piezoelectric element does not contain lead, anenvironmental burden can be reduced, and the power generator equippedwith a piezoelectric element that can maintain excellent characteristicsin a wide use environment temperature range can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described with reference to theaccompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a graph plotting an example of a phase diagram for describinga piezoelectric material according to an aspect of the invention.

FIG. 2 is a graph plotting an example of a phase diagram for describingthe piezoelectric material according to the aspect of the invention.

FIG. 3 is a graph plotting an example of a phase diagram for describingthe piezoelectric material according to the aspect of the invention.

FIG. 4 is an exploded perspective view illustrating a schematicconfiguration of a recording head according to a first embodiment of theinvention.

FIG. 5 is a plan view of the recording head according to the firstembodiment of the invention.

FIG. 6 is a cross-sectional view of the recording head according to thefirst embodiment of the invention.

FIG. 7 is a diagram illustrating a schematic configuration of arecording apparatus according to an embodiment of the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the invention will be described in detail based onembodiments.

Piezoelectric Material

A piezoelectric material contains a first component that is arhombohedral crystal in a single composition and that is configured tohave a complex oxide with a perovskite structure and Curie temperatureis set to be Tc1, a second component that is a crystal other than therhombohedral crystal in a single composition and that is configured tohave a complex oxide with the perovskite structure and Curie temperatureis set to be Tc2, and a third component that is a rhombohedral crystalin a single composition and that is configured to have a complex oxidewith the perovskite structure but Curie temperature is set to be Tc3different from the first composition, Tc2 is higher than Tc1, Tc3 isequal to or higher than Tc2, and the value of (0.1×Tc1+0.9×Tc2) is equalto or lower than 280° C.

With the piezoelectric material which is obtained by forming a solidsolution of the first component, the second component, and the thirdcomponent, each of which satisfies the above conditions, an MPB line canbe made substantially vertically erect in a phase diagram that employs acomposition ratio of the first component and the third component to thesecond component for the horizontal axis and temperature for thevertical axis.

Here, in a phase diagram that employs a ratio of the second component tothe sum of the first component and the second component (the secondcomponent/(the first component+the second component)) for the horizontalaxis, and temperature for the vertical axis, a line connecting Tc1 ofthe first component that is formed as the rhombohedral crystal and Tc2of the second component that is formed as a crystal other than therhombohedral crystal, for example, a tetragonal crystal is inclined, andthe MPB line is inclined as well. In addition, since the value of(0.1×Tc1+0.9×Tc2) is equal to or lower than 280° C., all Tcs are alsoequal to or lower than 280° C. Thus, when Curie temperature To in such acomposition of the material is lower than 280° C. that is compared tothat of PZT and a temperature of a use environment changes, acharacteristic of temperature dependency of a piezoelectriccharacteristic and a dielectric characteristic caused by low Tc isexhibited.

By adding the third component which is the rhombohedral crystalsatisfying the condition described above to the system, Tc of thecomposition of the first component and the third component which arerhombohedral crystal increases, and accordingly, the MPB line in a phasediagram that employs a composition ratio of the second component to thesum of the first component, the second component and the third componentfor the horizontal axis and temperature for the vertical axis goesalmost vertically erect. Thus, preferably, as a composition along theMPB line is used, Curie temperature Tc4 of the composition becomes equalto or higher than 280° C., and accordingly, a piezoelectric materialthat can maintain its characteristic almost stably even when thetemperature of a use environment changes can be realized.

Therefore, the composition of the piezoelectric material, a compositionin which the first component, the second component, and the thirdcomponent described above form a solid solution, has a composition nearthe MPB line in the phase diagram that employs a ratio of the secondcomponent to the sum of the first component, the second component andthe third component (the second component/(the first component+thesecond component+the third component)) for the horizontal axis andtemperature for the vertical axis, and Curie temperature Tc4 of thecomposition is set to be equal to or higher than 280° C.

Here, the MPB line is a boundary for creating different crystal systems,a crystal system has composition dependency, and a dielectric constant,a piezoelectric constant, and a Young's modulus have compositiondependency. Thus, in a composition that forms the MPB line, a dielectricconstant and a piezoelectric constant have a maximum value, and aYoung's modulus has a minimum value. A composition region is defined fora dielectric constant and a piezoelectric constant in which thecharacteristics are exhibited within the range of 70% or more of a peakvalue (a value on the MPB), and a composition region for a Young'smodulus in which the characteristic is within the range of 130% of theminimum value as compositions near MPB.

Here, it is preferable that the molar ratio of (the first component+thethird component) to (the first component+the second component+the thirdcomponent) be 0.1 to 0.9. By appropriately selecting the firstcomponent, the second component, and the third component, theabove-described effect can be exhibited in a wide range of composition.

In addition, it is preferable that the molar ratio of the thirdcomponent to (the first component+the third component) is 0.05 to 0.49.By being added to a combination of the first component having relativelylow Curie temperature Tc and the second component having relatively highCurie temperature and effectively acting therein, the third componentraises the Curie temperature Tc4 of the whole composition to 280° C. orhigher, thereby causing the MPB line to rise almost vertically, and thusrealizes a piezoelectric material of which the characteristic does notsignificantly change even when the temperature of a use environmentchanges. Even though an addition amount of the third component changesaccording to a composition of the combination, effective action can beexhibited as long as the component is added in the above-describedrange.

Examples of each of the first component, the second component, and thethird component which can be applied to the piezoelectric material areshown below.

For example, the first component is Ba(XTi)O₃ (wherein X is at least onekind selected from Zr, Sn, and Hf), the second component is (K, Na)NbO₃to which at least one kind of Sr and Ti is added, and the thirdcomponent is Bi(Fe, Mn)O₃.

In addition, the first component is Ba(Sn, Ti)O₃, the second componentis (K, Na)NbO₃ to which at least one kind of Li, Sb, and Ta is added,and the third component is Bi(Fe, Mn)O₃.

In addition, the first component is Ba(Hf, Ti)O₃, the second componentis (K, Na)NbO₃ to which at least one kind of Li, Sb, and Ta is added,and the third component is Bi(Fe, Mn)O₃.

Hereinafter, description will be provided in more detail with specificexamples.

FIG. 1 illustrates a phase diagram that employs a ratio of the firstcomponent to the sum of the second component and the second component(the second component/(the first component+the second component)) forthe horizontal axis, and temperature for the vertical axis, when thefirst component is Ba(Zr, Ti)O₃ and the second component is (K, Na)NbO₃to which Sr is added. In this case, Curie temperature Tc of Ba(Zr, Ti)O₃that is the first component is 70° C., Curie temperature of (K, Na)NbO₃to which Sr is added which is the second component is 277° C., and theMPB line m1 is inclined in the range of 0.75 to 0.60 of the compositionratio of the second component. When Bi(Fe, Mn)O3 that is the thirdcomponent (having Curie temperature Tc3 of 850° C.) is mixed with thesystem in the ratio of 0.30 to the sum of the first component and thethird component, Curie temperature of the composition of the firstcomponent and the third component is 300° C. The MPB line M1 in thephase diagram that employs the ratio of the second component to the sumof the first component, the second component and the third component(second component/(the first component+the second component+the thirdcomponent)) for the horizontal axis is almost vertically erect, andtransitioned in the range of the second component of 0.68 to 0.6.Accordingly, a piezoelectric material that has a remarkablepiezoelectric characteristic and dielectric characteristic in a wide useenvironment temperature range and has a high Curie temperature can berealized. Here, the phase diagram includes a composition range (denotedby R in the drawing) formed as a rhombohedral crystal, a compositionrange formed as a tetragonal crystal (denoted by T in the drawing) or anorthorhombic crystal (denoted by O in the drawing), and a compositionrange formed as a cubical crystal (denoted by C in the drawing).

Here, as piezoelectric characteristics of an MPB composition at roomtemperature of a piezoelectric body composed only by the first componentand the second component, while d33 is 150 pC/N and a Young's modulus isabout 85 GPa, and as characteristics of a MPB composition at roomtemperature when the third component is added, d33 is 250 pC/N and aYoung's modulus is 65 GPa. Thus, when a piezoelectric element,particularly an actuator is configured using such a piezoelectricmaterial, it can be easily anticipated that significant displacement isobtained.

When the piezoelectric element is used as an actuator, the range of thepiezoelectric characteristics d33 is preferably 100 to 300 pC/N, andmore preferably 150 to 300 pC/N. In this case, the range of a Young'smodulus is preferably 30 to 80 GPa, and the range of Curie temperatureTc is preferably 70 to 350° C. and more preferably 100 to 300° C. Inaddition, the range of relative permittivity is preferably equal to orless than 2000 and more preferably 100 to 1000.

In addition, when the piezoelectric element is used as a sensor, therange of an e constant is preferably 3 to 15 C/m² and more preferably 5to 15 C/m². In addition, in this case, the range of a Young's modulus ispreferably 70 to 150 GPa and more preferably 80 to 130 GPa. In addition,the range of Curie temperature Tc is preferably 100 to 350° C. and morepreferably 120 to 300° C. In addition, the range of relativepermittivity is preferably equal to or less than 2000 and morepreferably 100 to 800.

FIG. 2 illustrates a phase diagram that employs a ratio of the secondcomponent to the sum of the first component and the second component(the second component/(the first component+the second component)) forthe horizontal axis, and temperature for the vertical axis, when thefirst component is Ba(Sn, Ti)O₃ and the second component is (K, Na)NbO₃to which Li is added. In this case, Curie temperature Tc of Ba(Sn, Ti)O₃that is the first component is 50° C., Curie temperature of (K, Na)NbO₃to which Li is added that is the second component is 270° C., and theMPB line m2 is inclined in the range of a composition ratio of thesecond component from 0.67 to 0.40. When Bi(Fe, Mn)O₃ that is the thirdcomponent (having Curie temperature Tc3 of 850° C.) is mixed with thesystem at a ratio of 0.35 to the sum of the first component and thethird component, Curie temperature of the composition of the firstcomponent and the third component is 343° C. The MPB line M2 in thephase diagram that employs a ratio of the second component to the sum ofthe first component, the second component and the third component forthe horizontal axis is almost vertically erect, and the compositionratio of the second component is only transposed in the range of 0.57 to0.4. Accordingly, a piezoelectric material having a remarkablepiezoelectric characteristic and dielectric characteristic in a wide useenvironment temperature range and having a high Curie temperature can berealized.

Here, as the piezoelectric characteristics of an MPB composition at roomtemperature of a piezoelectric body composed only by the first componentand the second component, while d33 is 110 pC/N and a Young's modulus isabout 100 GPa, and as the piezoelectric characteristics of a MPBcomposition at room temperature when the third component is added, d33is 270 pc/N and a Young's modulus is 62 GPa. Thus, when a piezoelectricelement, particularly an actuator is configured using such apiezoelectric material, it can be easily anticipated that significantdisplacement is obtained.

FIG. 3 illustrates a phase diagram that employs a ratio of the secondcomponent to the sum of the first component and the second component(the second component/(the first component+the second component)) forthe horizontal axis, and temperature for the vertical axis, when thefirst component is Ba(Hf, Ti)O₃ and the second component is (K, Na)NbO₃to which Li is added. In this case, Curie temperature Tc of Ba(Hf, Ti)O₃that is the first component is 25° C., Curie temperature of (K, Na)NbO₃to which Li added that is the second component is 270° C., and the MPBline m3 is inclined in the range of a composition ratio of the secondcomponent from 0.59 to 0.32. When Bi(Fe, Mn)O₃ that is the thirdcomponent (having Curie temperature Tc3 of 850° C.) is mixed with thesystem at a ratio of 0.40 to the sum of the first component and thethird component, Curie temperature of the composition of the firstcomponent and the third component is 382° C. The MPB line M3 in thephase diagram that employs a ratio of the second component to the sum ofthe first component, the second component and the third component forthe horizontal axis is almost vertically erect, and just transitioned inthe range of the second component of 0.45 to 0.32. Accordingly, apiezoelectric material having a remarkable piezoelectric characteristicand dielectric characteristic in a wide use environment temperaturerange and a high Curie temperature can be realized.

Here, as the piezoelectric characteristics of an MPB composition at roomtemperature of a piezoelectric body composed only by the first componentand the second component, while d33 is 200 pC/N and a Young's modulus isabout 75 GPa, and as the piezoelectric characteristics of a MPBcomposition at room temperature when the third component is added, d33is 300 pC/N and a Young's modulus is 60 GPa. Thus, when a piezoelectricelement, particularly an actuator is configured using such apiezoelectric material, it can be easily anticipated that significantdisplacement is obtained.

Piezoelectric Element and Liquid Ejecting Head

FIG. 4 is an exploded perspective view showing a schematic configurationof an ink jet type recording head that is an example of a liquidejecting head equipped with the piezoelectric element according to anembodiment of the invention. FIG. 5 is a plan view of FIG. 4, and FIG. 6is a cross-sectional view taken by cutting along the line VI-VI of FIG.5. As illustrated in FIGS. 4 to 6, a flow path forming substrate 10 ofthe present embodiment is constituted by a silicon monocrystalsubstrate, and an elastic film 50 configured to have silicon dioxide isformed on one face of the substrate.

A plurality of pressure generating chambers 12 are provided in parallelin the flow path forming substrate 10 in the width direction of thesubstrate. In addition, a communication unit 13 is formed in an outerregion of the pressure generating chambers 12 in the longitudinaldirection of the flow path forming substrate 10, and the communicationunit 13 and each of the pressure generating chambers 12 communicate witheach other via ink supply paths 14 and communication paths 15 providedfor each of the pressure generating chambers 12. The communication unit13 constitutes a part of a manifold that serves as an ink chamber sharedby the pressure generating chambers 12 by communicating with a manifoldunit 31 of a protection substrate to be described later. The ink supplypaths 14 are formed having widths narrower than the pressure generatingchambers 12, and keeps resistance of ink flowing from the communicationunit 13 to the pressure generating chambers 12 against the flow pathconstant. Note that, in the present embodiment, the ink supply paths 14are formed by narrowing the width of the flow path from a single side,but the ink supply paths may be formed by narrowing the width of theflow path from both sides. In addition, the ink supply paths may beformed not by narrowing the width of the flow path but by narrowing thewidth in the thickness direction thereof. In the present embodiment, aliquid flow path constituted by the pressure generating chambers 12, thecommunication unit 13, the ink supply paths 14, and the communicationpaths 15 is provided in the flow path forming substrate 10.

In addition, a nozzle plate 20 in which nozzle openings 21, whichcommunicate with the pressure generating chambers 12 near the edge onthe opposite side of the ink supply paths 14, are drilled is fixed tothe flow path forming substrate 10 on the opening face side using anadhesive, a thermal welding film, or the like. Note that the nozzleplate 20 is formed of, for example, glass ceramics, a siliconmonocrystal substrate, stainless steel, or the like.

On the other hand, on the opposite side of the opening face of the flowpath forming substrate 10, the elastic film 50 described above isformed, and an adhesive layer 56 that is formed of titanium oxide forimproving adhesiveness to a base of first electrodes 60 such as theelastic film 50 is provided on the elastic film 50. Note that aninsulating film formed of zirconium oxide may be formed between theelastic film 50 and the adhesive layer 56 if necessary.

Further, the first electrodes 60, a piezoelectric layer 70 which is athin film having a thickness being equal to or thinner than 2 μm, orpreferably 0.3 to 1.5 μm, and second electrodes 80 are formed on theadhesive layer 56 in a laminating manner, configuring piezoelectricelements 300. Here, the piezoelectric element 300 refers to a portionincluding the first electrodes 60, the piezoelectric layer 70, and thesecond electrodes 80. Generally, one electrode of the electrodes of thepiezoelectric elements 300 is set to be a shared electrode, and theother electrode and the piezoelectric layer 70 are patterned for each ofthe pressure generating chambers 12. In the present embodiment, each ofthe first electrodes 60 is set to be a shared electrode of thepiezoelectric elements 300, and each of the second electrodes 80 is setto be an independent electrode of the piezoelectric elements 300, but itdoes not matter to reverse the setting according to a state of a drivecircuit or a wiring. In addition, here, the piezoelectric elements 300and a diaphragm of which displacement is caused due to driving of thepiezoelectric elements 300 are referred to as actuator devices. Notethat, in the example described above, the elastic film 50, the adhesivelayer 56, the first electrodes 60, and an insulating film that isprovided if necessary act as a diaphragm, but the configuration is ofcourse not limited thereto, and for example, the elastic film 50 or theadhesive layer 56 may not be provided. In addition, the piezoelectricelements 300 may also serve as a substantial diaphragm by themselves.

In the present embodiment, the piezoelectric layer 70 is formed of thepiezoelectric material described above. Since the piezoelectric materialhas a remarkable piezoelectric characteristic and dielectriccharacteristic in a wide use environment temperature range and has highCurie temperature, a piezoelectric element that exhibits an excellentdisplacement characteristic in a wide use environment temperature rangecan be realized. In addition, since the piezoelectric material does notcontain lead, an environmental burden can be reduced.

Each of the second electrodes 80 that is an independent electrode of thepiezoelectric elements 300 is drawn out from a periphery of an end ofthe ink supply path 14, and is connected to each of leading electrodes90 that is formed of, for example, gold (Au), or the like, extendingonto the adhesive layer 56.

With the flow path forming substrate 10 on which the piezoelectricelements 300 are formed as described above, in other words, on the firstelectrodes 60, the adhesive layer 56, and the leading electrodes 90, aprotection substrate 30 that has the manifold unit 31 constituting atleast a part of a manifold 100 is bonded via an adhesive 35. Themanifold unit 31 is formed passing through of the protection substrate30 in the thickness direction thereof to the pressure generatingchambers 12 in the width direction thereof, and communicates with thecommunication unit 13 of the flow path forming substrate 10 describedabove, thereby constituting the manifold 100 that serves as a shared inkchamber of the pressure generating chambers 12 in the presentembodiment. In addition, by dividing the communication unit 13 of theflow path forming substrate 10 into a plural number for each pressuregenerating chamber 12, only the manifold unit 31 may set to be amanifold. Further, for example, it may be configured that only thepressure generating chambers 12 are provided in the flow path formingsubstrate 10, and the ink supply path 14 that communicates with themanifold 100 and the pressure generating chambers 12 may be provided fora member (for example, the elastic film 50, the adhesive layer 56, orthe like) that is interposed between the flow path forming substrate 10and the protection substrate 30.

In addition, in a region of the protection substrate 30 facing thepiezoelectric elements 300, a piezoelectric element holding unit 32 thathas a space large enough for not disrupting motions of the piezoelectricelements 300 is provided. The piezoelectric element holding unit 32preferably has a space large enough for not disrupting motions of thepiezoelectric elements 300, and the space may or may not be sealed.

As the protection substrate 30 described above, a material havingsubstantially the same thermal expansion coefficient as the flow pathforming substrate 10, for example, glass, a ceramic material, or thelike is preferably used, and in the present embodiment, the projectionsubstrate is formed using a silicon monocrystal substrate that is thesame material as the flow path forming substrate 10.

In addition, a through hole 33 passing through the protection substrate30 in the thickness direction is provided in the protection substrate30. In addition, a part of an end of the leading electrode 90 drawn fromeach of the piezoelectric elements 300 is provided so as to be exposedwithin the through hole 33.

In addition, a drive circuit 120 for driving the piezoelectric elements300 which are installed parallel to each other is fixed onto theprotection substrate 30. As the drive circuit 120, for example, acircuit board, a semiconductor integrated circuit (IC), or the like canbe used. In addition, the drive circuit 120 and the leading electrode 90are electrically connected to each other via connection wiring 121formed of conductive wires such as bonding wires.

In addition, a compliance substrate 40 that includes a sealing film 41and a fixing plate 42 is bonded with the protection substrate 30. Here,the sealing film 41 is formed of a flexible material having lowrigidity, and one face of the manifold unit 31 is sealed by the sealingfilm 41. In addition, the fixing plate 42 is formed of a relatively hardmaterial. Since a region of the fixing plate 42 facing the manifold 100forms an opening 43 which is completely removed in the thicknessdirection, one face of the manifold 100 is sealed only by the flexiblesealing film 41.

In an ink jet type recording head I of the present embodiment, ink istaken from an ink inlet connected to an external ink supply unit that isnot shown in the drawing, the inside from the manifold 100 to nozzleopenings 21 is filled with ink, then a voltage is applied to spacesbetween the first electrodes 60 and the second electrodes 80 each ofwhich corresponds to the pressure generating chambers 12 according to arecording signal from the drive circuit 120, and accordingly, theelastic film 50, the adhesive layer 56, the first electrodes 60, and thepiezoelectric layer 70 are deflected, which causes pressure inside eachof the pressure generating chambers 12 to increase, and consequently inkdrops are discharged from the nozzle openings 21.

Next, an example of a method for manufacturing the piezoelectric elementof the ink jet type recording head of the present embodiment will bedescribed.

First, a silicon dioxide film formed of silicon dioxide (SiO₂), or thelike constituting the elastic film 50 is formed on a surface of a waferfor a flow path forming substrate that is a silicon wafer, using thermaloxidation or the like. Next, the adhesive layer 56 formed of titaniumoxide, or the like is formed on the elastic film 50 (silicon dioxidefilm) using a reactive sputtering method, thermal oxidation, or thelike.

Next, the first electrodes 60 are formed on the adhesive layer 56. To bespecific, the first electrode 60 that is formed of platinum, indium,indium oxide, a laminated structure of these, or the like is formed onthe adhesive layer 56. Note that the adhesive layer 56 and the firstelectrodes 60 can be formed using, for example, a sputtering method or avapor deposition method.

Next, the piezoelectric layer 70 is laminated on the first electrode 60.A manufacturing method of the piezoelectric layer 70 is not particularlylimited, but for example, the piezoelectric layer 70 can be formed usinga chemical solution method such as a Metal-Organic Decomposition (MOD)method or a gel-sol method in which a solution obtained by dissolving ordispersing an organic metal compound in a solvent is applied, dried, andthen burned at a high temperature, and thereby the piezoelectric layer70 formed of metal oxide is obtained. The piezoelectric layer 70 may beformed using other methods of a laser ablation method, the sputteringmethod, a pulsed laser deposition method (PLD method), a CVD method, anaerosol deposition method, or the like.

When the piezoelectric layer 70 is formed using, for example, a chemicalapplication method, 2-ethylhexanoate, acetate containing desiredelements are used as starting materials. For example, there are bismuth2-ethylhexanoate, barium 2-ethylhexanoate, iron 2-ethylhexanoate,titanium 2-ethylhexanate, and the like. A precursor solution is preparedby mixing n-octane solutions of the raw materials, and adjusting themolar ratio of the metal elements so as to match with a stoichiometricratio. Then, a piezoelectric film is formed using a spin coating methodin which the precursor solution is dropped onto a bottom electrode thatis produced beforehand, rotated for 6 seconds at 500 rpm, and then asubstrate is rotated for 20 seconds at 3000 rpm. Next, the substrate isplaced on a hot plate, and dried for 2 minutes at 180° C. Next, thesubstrate is placed on the hot plate, and then degreasing is performedfor 2 minutes at 350° C. After repeating the process from solutionapplication to degreasing twice, the substrate is fired for 5 minutes at750° C. using an RTA device in an oxygen atmosphere. Then, the processis repeated five times, and thereby a piezoelectric layer 70 can beformed through a total of 10 times of application.

After the piezoelectric layer 70 is formed as described above, thesecond electrodes 80 formed of platinum, or the like is formed on thepiezoelectric layer 70 using the sputtering method, or the like, thepiezoelectric layer 70 and the second electrodes 80 are patterned at thesame time in a region facing each of the pressure generating chambers12, and thereby the piezoelectric elements 300 configured to have thefirst electrodes 60, the piezoelectric layer 70, and the secondelectrodes 80 are formed. Note that the patterning of the piezoelectriclayer 70 and the second electrode 80 can be collectively performed usingdry etching via a resist (not shown in the drawing) that is formed in apredetermined shape. Then, post annealing may be performed in atemperature range of 600° C. to 800° C. if necessary. Accordingly, afavorable interface between the piezoelectric layer 70 and the firstelectrodes 60 or the second electrodes 80 can be formed, and acrystalline property of the piezoelectric layer 70 can improve.

Next, over the entire face of the wafer for a flow path formingsubstrate, the leading electrodes 90 formed of, for example, gold (Au),or the like are formed, and then, the electrodes are patterned for eachof the piezoelectric elements 300 via, for example, a mask pattern thatincludes a resist, or the like.

Next, after a wafer for a protection substrate that is a silicon waferand will serve as a plurality of the protection substrates 30 is bondedwith the piezoelectric elements 300 of the wafer for a flow path formingsubstrate using the adhesive 35, the wafer for a flow path formingsubstrate is thinned so as to have a predetermined thickness.

Next, a mask film is newly formed on the wafer for the flow path formingsubstrate, and patterned in a predetermined shape.

Then, by performing anisotropic etching (wet etching) on the wafer for aflow path forming substrate using an alkali solution such as KOH via themask film, the pressure generating chambers 12, the communication unit13, the ink supply path 14, and the communication path 15 correspondingto the piezoelectric elements 300 are formed.

Then, unnecessary portions of outer circumferential parts of the waferfor a flow path forming substrate and the wafer for a protectionsubstrate are cut so as to be removed using, for example, dicing, or thelike. Then, after the mask film of the face of the wafer for a flow pathforming substrate on the opposite side of the wafer for a protectionsubstrate is removed, the nozzle plate 20 through which the nozzleopenings 21 are drilled is bonded with the wafer for a flow path formingsubstrate, the compliance substrate 40 is bonded with the wafer for aprotection substrate, and then by dividing the wafer for a flow pathforming substrate into one-chip-sized flow path forming substrate 10,and the like as shown in FIG. 4, the ink jet type recording head I ofthe present embodiment is formed.

Example 1

Ba(Zr_(0.3), Ti_(0.7))O₃ was selected as the first component, (K_(0.5),Na_(0.5))NbO₃ to which Sr had been added was selected as the secondcomponent, and Bi(Fe_(0.95), Mn_(0.05))O₃ was selected as the thirdcomponent, and then a piezoelectric material having a composition inwhich the molar ratio of the three components is 0.36:0.44:0.20 wasformed as described below.

A precursor solution was prepared by mixing n-octane solutions of barium2-ethylhexanoate, zirconium 2-ethylhexanoate, titanium 2-ethylhexanoate,potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, niobium2-ethylhexanoate, bismuth 2-ethylhexanoate, iron 2-ethylhexanoate,manganese 2-ethylhexanoate, and strontium 2-ethylhexanoate as startingmaterials by adjusting the molar ratio of the metal elements so as tomatch with a stoichiometric ratio of the composition.

A piezoelectric film was formed using a spin coating method in which theprecursor solution was dropped onto a bottom electrode that had beenproduced beforehand, rotated for 6 seconds at 500 rpm, and then asubstrate was rotated for 20 seconds at 3000 rpm. Next, the substratewas placed on a hot plate and dried for 2 minutes at 180° C. Then, thesubstrate was placed on the hot plate to perform degreasing for 2minutes at 350° C. After repeating the process from solution applicationto degreasing twice, the substrate was burned for 5 minutes at 750° C.using an RTA device in an oxygen atmosphere. Then, the process wasrepeated five times, and thereby a piezoelectric layer was formedthrough a total of 10 times of application.

A head with the structure described above was configured usingpiezoelectric elements formed using the piezoelectric layer. d33 of thepiezoelectric element was 250 pC/N, and a Young's modulus thereof was 65GPa. On the other hand, when the third component was not added, d33thereof was 150 pC/N, and a Young's modulus thereof was about 85 GPa.Thus, when a piezoelectric element, particularly an actuator using thepiezoelectric material is configured, it can be easily anticipated thatsignificant displacement is obtained.

As clear from FIG. 1, Curie temperature increased from 184° C. to 293°C. with the addition of the third component. The value of 293° C. isequivalent to a value of Curie temperature of a PZT-based material thatis a so-called hard material. In the related art, it is believed that ahigh Curie temperature is not compatible with a remarkable piezoelectriccharacteristic, but due to the aspects of the invention, a high Curietemperature of a Pb-based material can be compatible with the remarkablepiezoelectric characteristic. When an environmental temperature isaround a Curie temperature, temperature dependency of the piezoelectriccharacteristic and the dielectric characteristic sharply increases, andas the environmental temperature is shifted to a low temperature sidefrom around the Curie temperature, temperature dependency of thepiezoelectric characteristic and the dielectric characteristic isgenerally lessened. Thus, for a general device having a drivingenvironment temperature around room temperature, a piezoelectricmaterial having a high Curie temperature is favorable in that thematerial guarantees stable characteristics.

Example 2

Ba(Sn_(0.3), Ti_(0.7))O₃ was selected as the first component, (K_(0.5),Na_(0.5))NbO₃ to which Li had been added was selected as the secondcomponent, and Bi(Fe_(0.95), Mn_(0.05))O₃ was selected as the thirdcomponent, and then a piezoelectric material having a composition inwhich the molar ratios of the three components are 0.43:0.37:0.23 wasformed as described below.

A precursor solution was prepared by mixing n-octane solutions of barium2-ethylhexanoate, tin 2-ethylhexanoate, titanium 2-ethylhexanoate,potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, niobium2-ethylhexanoate, bismuth 2-ethylhexanoate, iron 2-ethylhexanoate,manganese 2-ethylhexanoate, and lithium 2-ethylhexanoate as startingmaterials by adjusting the molar ratio of the metal elements so as tomatch with a stoichiometric ratio of the composition.

A piezoelectric film was formed using the spin coating method in whichthe precursor solution was dropped onto a bottom electrode that had beenproduced beforehand, rotated for 6 seconds at 500 rpm, and then asubstrate was rotated for 20 seconds at 3000 rpm. Next, the substratewas placed on a hot plate and dried for 2 minutes at 180° C. Then, thesubstrate was placed on the hot plate to perform degreasing for 2minutes at 350° C. After repeating the process from solution applicationto degreasing twice, the substrate was burned for 5 minutes at 750° C.using an RTA device in an oxygen atmosphere. Then, the process wasrepeated five times, and thereby a piezoelectric layer was formedthrough a total of 10 times of application.

A head with the structure described above was configured usingpiezoelectric elements formed using the piezoelectric layer. d33 of thepiezoelectric element was 270 pC/N, and a Young's modulus thereof was 62GPa. On the other hand, when the third component was not added, d33thereof was 110 pC/N, and a Young's modulus thereof was about 100 GPa.Thus, when the piezoelectric element, particularly an actuator using thepiezoelectric material is configured, it can be easily anticipated thatsignificant displacement is obtained.

As clear from FIG. 2, Curie temperature increased to 314° C. from 138°C. with the addition of the third component.

Example 3

Ba(Hf_(0.2), Ti_(0.8))O₃ was selected as the first component, (K_(0.5),Na_(0.5))NbO₃ to which Li had been added was selected as the secondcomponent, and Bi(Fe, Mn)O₃ was selected as the third component, andthen a piezoelectric material having a composition in which the molarratios of the three components are 0.36:0.40:0.24 was formed asdescribed below.

A precursor solution was prepared by mixing n-octane solutions of barium2-ethylhexanoate, hafnium 2-ethylhexanoate, titanium 2-ethylhexanoate,potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, niobium2-ethylhexanoate, bismuth 2-ethylhexanoate, iron 2-ethylhexanoate,manganese 2-ethylhexanoate, and lithium 2-ethylhexanoate as startingmaterials by adjusting the molar ratio of the metal elements so as tomatch with a stoichiometric ratio of the composition.

A piezoelectric film was formed using the spin coating method in whichthe precursor solution was dropped onto a bottom electrode that had beenproduced beforehand, rotated for 6 seconds at 500 rpm, and then asubstrate was rotated for 20 seconds at 3000 rpm. Next, the substratewas placed on a hot plate and dried for 2 minutes at 180° C. Then, thesubstrate was placed on the hot plate to perform degreasing for 2minutes at 350° C. After repeating the process from solution applicationto degreasing twice, the substrate was burned for 5 minutes at 750° C.using an RTA device in an oxygen atmosphere. Then, the process wasrepeated five times, and thereby a piezoelectric layer was formedthrough a total of 10 times of application.

A head with the structure described above was configured usingpiezoelectric elements formed using the piezoelectric layer. d33 of thepiezoelectric element was 300 pC/N, and a Young's modulus thereof was 60GPa. On the other hand, when the third component was not added, d33thereof was 200 pC/N, and a Young's modulus thereof was about 75 GPa.Thus, when the piezoelectric element, particularly an actuator using thepiezoelectric material is configured, it can be easily anticipated thatsignificant displacement is obtained.

Here, as characteristics of an MPB composition of a piezoelectricmaterial configured only by the first component and the second componentat room temperature, while d33 is 200 pC/N and a Young's modulus isabout 75 GPa, as the characteristics of an MPB composition at roomtemperature when the third component is added, d33 is 300 pC/N, and aYoung's modulus is 60 GPa. Thus, when the piezoelectric element,particularly an actuator using the piezoelectric material is configured,it can be easily anticipated that significant displacement is obtained.

As clear from FIG. 3, Curie temperature increased to 348° C. from 99° C.with the addition of the third component.

Other Embodiment for Piezoelectric Material

Hereinabove, an embodiment of the piezoelectric material of theinvention has been described, but a basic configuration of thepiezoelectric material of the invention is not limited to one describedabove.

Table 1 describes compositions (A site and B site) composing aperovskite-type crystal (ABO₃ wherein A and B are metal elements),crystal systems and Curie temperature Tc thereof. Since an MPB can beformed with a combination of different crystal systems, improvement ofpiezoelectric performance and Curie temperature Tc can be achieved evenwith the following combinations.

-   -   I Tetragonal system and orthorhombic system    -   II Tetragonal system and monoclinic system    -   III Orthorhombic system and monoclinic system

Thus, the elements can be arbitrarily selected so that a combination ofcrystal systems different from Table 1 can be realized. In this case,Tc1, Tc2, and Tc3 can be selected by adjusting an additive and an amountof addition. As elements appropriate for the additive, the followingelements are exemplified in addition to the elements noted on Table 1:

-   -   Mn, Ge, Si, B, Cu, and Ag.

TABLE 1 CRYSTAL SYSTEM (AT ROOM A SITE B SITE Tc ADDITIVE TEMPERATURE)Ag Nb 67 M Bi NiTi 225 M Ba HfTi 25 R Ba SnTi 50 R Ba ZrTi 70 R NaBi Ti200 R BiNa Ti 268 Sr R BiNa Ti 268 Ca R BiNaBa Ti 280 R BiNa Ti 320 RBiNa Ti 200~350 Li, La R BiLa ZnTi 350 R BiNa ScTi 358 R Ag Ta 370 R BaBi 370 R Bi MgTi 395 R Si Sc 400 R Bi Sc 480 R Bi Fe 850 R BiNaLa Ti335-370 R K Nb 200~435 Sr, Li, Sb, Ta O K Na Nb 200~435 Sr, Li, Sb, Ta ONa Nb 365 O Na Ta 480 O Cd Hf 600 O Sr Zr 700 O Ca Ti 1260 O BaCa Ti 70T Ba Ti 123 T Na Nb 360 T BiK Ti 380 T Kbi Ti 550 T * T: Tetragonalsystem * R: Rhombohedral system * M: Monoclinic system * O: Orthorhombicsystem

OTHER EMBODIMENT

Hereinabove, embodiments of the invention have been described, but abasic configuration of the invention is not limited to ones describedabove. Although, for example, a silicon monocrystal substrate isexemplified as the flow path forming substrate 10 in the embodimentdescribed above, the substrate is not particularly limited thereto, anda material, for example, an SOI substrate, glass, or the like may beused.

Further, in the embodiment described above, although the piezoelectricelements 300 obtained by laminating the first electrodes 60, thepiezoelectric layer 70, and the second electrodes 80 on a substrate (theflow path forming substrate 10) in order are exemplified, they are notlimited particularly thereto, and the invention can also be applied to alongitudinal oscillation type piezoelectric element in whichpiezoelectric materials and electrode forming materials are laminated inan alternate manner and extend in an axial direction.

The piezoelectric layer may not be a thin film as described above, butmay be a bulk member. When the layer is formed as a bulk member,carbonate or oxide is used as a starting material. Examples are K₂CO₃,Na₂CO₃, Nb₂O₅, and the like. The starting materials are measured so asto match with a stoichiometric ratio and then wet-blended with ethanolusing a ball mill. After the obtained mixture is dried, it is calcinedfor 3 hours at 700° C. The calcined powder is pulverized and mixed usingmortar with addition of an appropriate amount of PVA as a binder, and iscaused to pass through a sieve of 150 mesh to adjust granularitythereof, and then the obtained powder is formed into a discoid palletusing a single-axis press device. Next, the formed pallet and residualcalcined powder are put into a melting pot and burned for 3 hours at1100° C., thereby obtaining a discoid oxide. Then, both faces of theobtained discoid oxide are polished so as to have surfaces, are coatedwith silver paste and burned, and accordingly, a piezoelectric bodyprovided with silver electrodes can be obtained. Note that, in themanufacturing of the piezoelectric body in bulk, barium carbonate,titanium oxide, bismuth oxide, tin oxide, iron oxide, zirconium oxide,lanthanum oxide, lithium carbonate, and the like can be exemplified asstarting materials.

In addition, the ink jet type recording head of the embodimentconstitutes a part of a recording head unit provided with an ink flowpath that communicates with an ink cartridge, or the like, and ismounted in an ink jet type recording apparatus. FIG. 7 is a schematicdiagram illustrating an example of such an ink jet type recordingapparatus.

As illustrated in FIG. 7, recording head units 1A and 1B that have theink jet type recording head I are provided so as to enable cartridges 2Aand 2B constituting an ink supply unit to attach to and detach from theunits, and a carriage 3 on which the recording head units 1A and 1B aremounted is provided so as to freely move on a carriage shaft 5 installedin the main body 4 of the apparatus in the axial direction. Therecording head units 1A and 1B are respectively set to discharge a blackink composition and a color ink composition.

In addition, drive force of a drive motor 6 is transmitted to thecarriage 3 via a plurality of gear wheels, which are not shown in thedrawing, and a timing belt 7, and accordingly, the carriage 3 on whichthe recording head units 1A and 1B are mounted is moved along thecarriage shaft 5. On the other hand, the main body 4 of the apparatus isprovided with a platen 8 along the carriage shaft 5, and a recordingsheet S that is a recording medium such as paper fed by a feedingroller, or the like, which is not shown in the drawing, is designed tobe wounded around the platen 8 and then transported.

In the example illustrated in FIG. 7, although the ink jet typerecording head units 1A and 1B are set to respectively have one ink jettype recording head I, they are not particularly limited thereto, andfor example, either of the ink jet type recording head units 1A or 1Bmay have two or more ink jet type recording heads.

Note that, in the embodiment described above, the ink jet type recordinghead is exemplified as an example of a liquid ejecting head, however,the invention widely targets liquid ejecting heads in general, and canof course be applied to liquid ejecting heads that eject liquid otherthan ink. As other liquid ejecting heads, for example, various recordingheads used in image recording apparatuses such as printers, colormaterial ejecting heads used in manufacturing of color filters of liquidcrystal displays, electrode material ejecting heads used in formation ofelectrodes of organic EL displays, field emission displays (FED),bioorganic substance ejecting heads used in manufacturing of bio chips,and the like can be exemplified.

Ultrasonic Sensor and Piezoelectric Motor

Since the above piezoelectric element exhibits a satisfactory insulatingproperty and piezoelectric characteristic, it can be applied to apiezoelectric element of a liquid ejecting head represented by an inkjet-type recording head as described above, however, it is not limitedthereto. Since the above piezoelectric element exhibits an excellentdisplacement characteristic, it is not limited to the liquid ejectinghead represented by an ink jet-type recording head, it can beappropriately used by being mounted on liquid ejecting apparatuses,ultrasonic sensors, piezoelectric motors, ultrasonic motors,piezoelectric transformers, oscillation-type dust removal apparatuses,pressure-electric converters, ultrasonic wave transmitting machines,pressure sensors, acceleration sensors, or the like.

Power Generator

In addition, since the piezoelectric element exhibits a satisfactoryenergy-electric conversion capability, it can be appropriately used bybeing mounted on a power generator. Examples of the power generatorinclude a power generator using a pressure-electric conversion effect, apower generator using an electronic excitation (photovoltaic power) bylight, a power generator using an electronic excitation (thermo-electricforce) by heat, and a power generator using oscillating.

Note that, the piezoelectric element can be appropriately used inpyroelectric device such as infrared detectors, terahertz detectors,temperature sensors, and thermo-sensitive sensors or ferroelectricelements such as a ferroelectric memory.

The entire disclosures of Japanese Patent Application Nos. 2013-137279filed Jun. 28, 2013 and 2014-001900 filed Jan. 8, 2014 are expresslyincorporated by reference herein.

What is claimed is:
 1. A piezoelectric material containing: a firstcomponent that is a rhombohedral crystal and that has a complex oxidewith a perovskite structure and Curie temperature Tc1; a secondcomponent that is a crystal other than a rhombohedral crystal and has acomplex oxide with the perovskite structure and Curie temperature Tc2;and a third component that is a rhombohedral crystal and has a complexoxide with the perovskite structure and Curie temperature Tc3, the thirdcomponent being different from the first component, wherein Tc2 ishigher than Tc1, Tc3 is equal to or higher than Tc2, and a value of(0.1×Tc1+0.9×Tc2) is equal to or lower than 280° C.
 2. The piezoelectricmaterial according to claim 1, wherein a composition of thepiezoelectric material is near an MPB line in a phase diagram thatemploys a ratio of the second component to the sum of the firstcomponent, the second component and the third component (the secondcomponent/the first component+the second components+the third component)for a horizontal axis, and temperature for a vertical axis, and whereina Curie temperature Tc4 of the composition is equal to or higher than280° C.
 3. The piezoelectric material according to claim 1, wherein amolar ratio of (the first component+the third component) to (the firstcomponent+the second component+the third component) is 0.1 to 0.9. 4.The piezoelectric material according to claim 1, wherein a molar ratioof the third component to (the first component+the third component) is0.05 to 0.49.
 5. The piezoelectric material according to claim 1,wherein the first component is Ba(XTi)O₃, the second component is (K,Na)NbO₃ to which at least one of Sr and Ti is added, and the thirdcomponent is Bi(Fe, Mn)O₃, wherein X is at least one of Zr, Sn, and Hf.6. The piezoelectric material according to claim 1, wherein the firstcomponent is Ba(Zr, Ti)O₃, the second component is (K, Na)NbO₃ to whichat least one of Sr and Ti is added, and the third component is Bi(Fe,Mn)O₃.
 7. The piezoelectric material according to claim 1, wherein thefirst component is Ba(Sn, Ti)O₃, the second component is (K, Na)NbO₃ towhich at least one of Li, Sb and Ta is added, and the third component isBi(Fe, Mn)O₃.
 8. The piezoelectric material according to claim 1,wherein the first component is Ba(Hf, Ti)O₃, the second component is (K,Na)NbO₃ to which at least one of Li, Sb and Ta is added, and the thirdcomponent is Bi(Fe, Mn)O₃.
 9. A piezoelectric element comprising: apiezoelectric layer formed of the piezoelectric material according toclaim 1; and an electrode provided on the piezoelectric layer.
 10. Apiezoelectric element comprising: a piezoelectric layer formed of thepiezoelectric material according to claim 2; and an electrode providedon the piezoelectric layer.
 11. A piezoelectric element comprising: apiezoelectric layer formed of the piezoelectric material according toclaim 3; and an electrode provided on the piezoelectric layer.
 12. Apiezoelectric element comprising: a piezoelectric layer formed of thepiezoelectric material according to claim 4; and an electrode providedon the piezoelectric layer.
 13. A piezoelectric element comprising: apiezoelectric layer formed of the piezoelectric material according toclaim 5; and an electrode provided on the piezoelectric layer.
 14. Apiezoelectric element comprising: a piezoelectric layer formed of thepiezoelectric material according to claim 6; and an electrode providedon the piezoelectric layer.
 15. A piezoelectric element comprising: apiezoelectric layer formed of the piezoelectric material according toclaim 7; and an electrode provided on the piezoelectric layer.
 16. Aliquid ejecting head comprising: a pressure generating chamber thatcommunicates with a nozzle opening; and a piezoelectric element that hasa piezoelectric layer and an electrode provided on the piezoelectriclayer, wherein the piezoelectric layer is formed of the piezoelectricmaterial according to claim
 1. 17. A liquid ejecting apparatuscomprising: the liquid ejecting head according to claim
 16. 18. Anultrasonic sensor comprising: a vibrating unit that transmits adisplacement which is caused due to driving of the piezoelectric elementaccording to claim 9 to the outside; and a matching layer that transmitsa generated pressure wave to the outside.
 19. A piezoelectric motorcomprising: at least a vibrator in which the piezoelectric elementaccording to claim 9 is arranged, and a moving body contacting thevibrator.
 20. A power generator comprising: an electrode taking out acharge generated by the piezoelectric element according to claim 9.